1. Field of the Invention
The invention relates to an apparatus for removing surface coverings and methods for using such apparatus. More particularly, it relates to powered apparatus for removing surface coverings from roofs, including inclined or flat roofs, or from the sides of buildings, or both. Still more particularly, the present invention relates to apparatus having a double-acting cylinder powered by compressed air for removing surface coverings from roofs or from the sides of buildings, or both.
2. Description of Related Art
The exterior surfaces of buildings may be covered with a plurality of overlapping, horizontally aligned rows of shingles. The first row of shingles generally is laid across the lowermost edge of the surface to be covered and fastened, e.g., nailed or stapled, in place at the upper portion of the shingle. Some building surfaces are covered with roll roofing, in which successive sheets of roofing material are overlapped in a similar manner. Roofs for frame houses, particularly roofs which have a wooden roof surface, may be covered with a plurality of layers of roofing materials, such as asphalt shingle or artificial slate. The outer layers are formed by roofing shingles which are somewhat flexible and are formed with projecting, separated flaps, which overlie and are horizontally staggered with respect to a lower course of shingles. Thus, each portion of the roofing surface is covered by a plurality of layers, for example, formed by roofing felt or roofing paper, and then by a first layer of shingles.
Over time, roofing shingles wear out, deteriorate, or suffer damage and lose their effectiveness. Such shingles require periodic removal and replacement. When the shingles wear out or deteriorate, that is, when the surface granulation thereof has worn off, or if the roof becomes damaged due to storms, a second layer of shingles may be laid over the existing shingles. When a shingle roof is replaced, the old shingles may be removed and discarded and replaced by new shingles. Normally, before a new roof is installed on a building, the damaged roofing material is removed. Thus, at some point in the buildings lifetime, it is likely to be necessary to remove a layer or layers of shingles which are already on the roof.
Generally, shingles are fastened, e.g., nailed or stapled, to the roof surface. Roofing nails which have wide flat heads may be used, so that the nails may securely hold the shingle material to the roof surface. The fasteners, e.g., nails, staples, or the like, may not be visible or exposed to weather. As noted above, the fasteners may be placed along the upper edge portion of the shingles of any one course, so that, when the next course of shingles is laid thereover, the fasteners are hidden under the flaps of the succeeding shingles. Because these succeeding shingles are fastened, e.g., nailed or stapled, and held down in the same manner, it may not be possible to merely raise any one flap of a shingle in order to gain access to the fasteners. The flaps frequently hide the fasteners and the succeeding layer of flaps, ascending toward the crown of the roof, tend to hold down the preceding ones. This hold-down effect is a significant reliability feature, maintaining the integrity of the roof under windy or stormy conditions.
To remove the shingles, problems arise in obtaining access to the fasteners. To obtain access to the fasteners and to pry the fasteners up on a fastener-by-fastener, especially, if two layers of shingles are on the roof surface, may be extremely time consuming. During removal the shingles often split or rip, littering the shingled surface with debris which must be removed before a new protective surface may be applied. The roofing fasteners employed to hold down the shingles may tear through the shingles during the lifting process and remain imbedded in the underlying roof surface. After the shingles have been stripped, the remaining fasteners protrude from the roof surface and are either withdrawn from the roof surface or driven down into the roof surface to allow for the application of the new roofing materials. Withdrawing the old roofing fasteners or driving them into the roof surface increases the total required time for removal of the old roofing materials and installation of the new roofing materials, thereby increasing the total cost of the roofing replacement operation.
Proper preparation of an existing roof for replacement shingle installation may be a difficult and time consuming job. Except where only small patches of the roof are to be repaired, a more common practice is to remove very large sections of the old shingles prior to installation of replacements. At present, shingles may be removed manually through a variety of known hand tools. Such tools are often cumbersome to operate, and their use may result in wasted man hours. The steep and often dangerous pitch of known roofs further aggravates the problems encountered in removing shingles with known hand tools.
Pry bars with extending blades exist, which are configured to fit beneath a layer or layers of shingles, or between the roof surface and a layer or layers of shingles, so that a plurality of fasteners may be pried up from the roof surface at one time. Such pry bars, however, tend to deform or break. Moreover, such manual removal processes are tedious, repetitive, laborious, and exhaustive. One or more roofers manually and repeatedly insert the tool beneath a free edge of a shingle layer or layers and pry upwardly to withdraw the fasteners from the roof surface and free the shingles for removal.
In addition, such roofing material removal tools may include a leading flat portion which is intended to be oriented substantially parallel to the surface on which the roofing materials are connected. However, the orientation of the leading edge of the head of the tool may be a function of a number of factors. Such factors include the angular orientation between the handle and the leading edge of the tool, the length of the handle and the height at which the roofer holds the handle in relation to the surface on which the tiles are mounted. The latter factor also tends to be a function of the roofer's height, and whether the roofer holds the handle in a position that is comfortable for the roofer during use, or whether the roofer is compelled to artificially raise or lower the tool, or both, during use.
Back injuries may not result from a single incident or trauma. Repetitive bending or lifting and remaining in awkward postures for prolonged periods, however, may tire back muscles and result in ligament sprains. Sprains occur when back muscles are no longer able to respond to repetitive movements. See Joel Martin, Professional Roofing, www.professionalroofing.net (October 1999). Removing roofing materials by means of such known hand tools may increase significantly the likelihood of back injury.
Various power tools have been developed in an effort to overcome the disadvantages of manual removal processes. While powered, shingle removing tools have been proposed, such tools have suffered from various drawbacks in actual practice. Thus, for example, some such removal tools have not provided appropriate leverage or mechanical advantage at the tip edge of the blade to quickly and conveniently remove shingles.